What’s in a Name? Dietary Zeaxanthin vs. Meso-Zeaxanthin

What’s this article about?

I’ve received many inquiries about the difference between dietary zeaxanthinand meso-zeaxanthin. There is significant market confusion about products containing the name, “zeaxanthin”, so I felt it important to address the most common questions and issues.

What is the new “meso-free” emblem in your website?

A group of reputable Zeaxanthin suppliers and manufacturers have created a “Free of Meso-Zeaxanthin” emblem (see top of this email) to help the public accurately identifmeso freey the contents of supplements containing Zeaxanthin. Available to supplement manufacturers who want to assure customers that their products contain only dietary zeaxanthin (vs. synthetic meso-zeaxanthin), the emblem was developed by the Zeaxanthin Trade Association (ZTA) to assure the public of a quality source of dietary zeaxanthin, which is free of meso-zeaxanthin.

What is Meso-Zeaxanthin?

Though not fully vetted or approved as New Dietary Ingredient (NDI – see below), meso-zeaxanthin is a synthetic ingredient widely available in the US market. There are a variety of legal and safety issues of which EyeCare Professionals should be aware when choosing an ocular supplement for their patients.

There are three chemical isomers (structures) of Zeaxanthin:

1. (R-R): the only form of Zeaxanthin found naturally in food.
2. (R-S): meso-zeaxanthin, a form found in the primate retina but nowhere else in the body.
3. (S-S): “unnatural” zeaxanthin – not found in nature.

 

What are the important issues?

1. Legal
2. Truthful disclosure
3. Safety/Efficacy

Legal

Meso-zeaxanthin is not a legal dietary supplement ingredient in the U.S. Dietary supplements are regulated by the FDA and FTC. The FDA follows the 1994 DSHEA law. The 2011 Food Safety Modernization Act also highlights important safety requirements that are applicable to supplement ingredients and manufacturers.

Per DSHEA law, the FDA requires a legal application and approval process for dietary supplement ingredients that were not in the US market before 1994 or which have been chemically altered. Meso-zeaxanthin is not in the American diet and is created by harsh chemical modification of a crude marigold extract. Therefore, it is a New Ingredient, but to date an NDI for meso-zeaxanthin has not been filed with or approved by the FDA to demonstrate safety.

A 2010 USDA food source survey (sponsored by ZTA) was unable to detect meso-zeaxanthin in any foods. Recently, one supplier filed a self-affirmation GRAS petition for a mixture of lutein, zeaxanthin and meso-zeaxanthin for use as a food additive, but this petition is different than an NDI for dietary supplements.

Truthful disclosure

Truthful disclosure is the purview of the FTC and it oversees truthful advertising and communications to the consumer (and patients). Many consumers, patients and EyeCare professionals have heard about the health benefits of lutein and zeaxanthin and the foods that contain them.

The AREDS-2 trial is using only dietary zeaxanthin, not meso-zeaxanthin in its government sponsored trial. Meso-zeaxanthin is currently imported from a group of suppliers in India, China and Mexico – none of which have FDA oversight.

A recent survey of supplements for sale in the U.S. shockingly identified that a majority were labeled “zeaxanthin” but actually contained meso-zeaxanthin at varying levels. (mislabeling) In addition, the third and unnatural form of Zeaxanthin (S-S) was actually found in several products!

Additional information about meso-zeaxanthin is available at this link: www.zeavision.com/positionpaper

Safety/Efficacy

The safety of lutein and dietary zeaxanthin have been directly reviewed and approved in more than half a dozen NDI and GRAS petitions to the FDA, even though both have always been in the human diet.
So, the outstanding questions are;

1) Is it true that the primate eye converts lutein into meso-zeaxanthin (only in the retina) because it prefers the dietary form of carotenoids?

2) What is the impact of meso-zeaxanthin in the rest of the body? (Unknown)

3) What else is contained in imported ingredients not examined by the FDA?

4) What is the evidence of meso-zeaxanthin benefits?

Summary

No meso-zeaxanthin publications exist that demonstrate it has been tested by itself without other carotenoids, so any beneficial effects are unknown. This is also true regarding whether Macular Pigment Optical Density (MPOD) can actually be increased by meso-zeaxanthin alone.

There are 3 or 4 human meso-zeaxanthin supplementation reports that concur there is poor uptake of meso-zeaxanthin into the blood. These particular reports do not resolve whether meso-zeaxanthin competitively inhibits uptake of the other two carotenoids, zeaxanthin and lutein though questions have been raised.

If you have additional questions, comments, or observations, feel free to contact ZeaVision at support@zeavision.com or by calling us at 1-866-833-2800.

Dennis Gierhart, PhD
Founder and CSO
ZeaVision, LLC